This invention relates in general to screw and nut mechanisms and has specific reference to a releasable mechanism of this type.
Screw and nut mechanisms of the bearing type comprise as a rule an internal screw, a coaxial external nut or socket, the outer diameter of said screw being smaller than the inner diameter of the nut so as to provide therebetween a free annular gap in which rolling members such as planet rollers or balls whether screw-threaded or formed with annular grooves are provided, said rollings members engaging simultaneously the screw threads and the nut threads, so that the relative rotation of the screw in the nut will produce rolling frictional contacts and thus reduce sliding contacts to a nearly negligible value.
These known mechanisms comprise of course suitable means for recycling the rollers or balls and restoring them to their initial position when the relative angular movement of the screw in the nut or socket has caused an axial movement of the balls or rollers equal to one screw pitch.